Homemade Sweet Onion Sauce is a delightful blend of sweet and tangy flavors that elevates any meal. This easy copycat recipe captures the essence of Subway’s famous sauce, making it perfect for sandwiches, salads, and dipping. Whether you’re hosting a gathering or just want to add some flair to your weeknight dinner, this sauce will impress with its unique taste and versatility.

Why You’ll Love This Recipe
- Quick and Easy: With only 15 minutes of total time, you can whip up this delicious sauce in no time.
- Versatile Use: Perfect for sandwiches, salads, or as a dip for veggies, this sauce fits multiple occasions.
- Fresh Ingredients: Using simple pantry staples ensures a homemade flavor without any preservatives.
- Customizable Flavor: Adjust the sweetness or tanginess to suit your preference by tweaking the vinegar or sugar amounts.
- Vegan-Friendly: This recipe is entirely plant-based, making it suitable for vegan diets and anyone looking to enjoy lighter condiments.
Tools and Preparation
To prepare your Homemade Sweet Onion Sauce, having the right tools will make the process smooth and efficient.
Essential Tools and Equipment
- Saucepan
- Whisk
- Airtight container
Importance of Each Tool
- Saucepan: Essential for heating and mixing ingredients evenly.
- Whisk: Helps achieve a smooth consistency by blending all components thoroughly.
- Airtight container: Keeps your sauce fresh in the refrigerator for up to one week.
Ingredients
Recreate Subway’s famous sweet onion sauce with this easy copycat recipe. Perfect blend of sweet and tangy flavors.
For the Sauce
- 1 Cup Sugar
- 1/2 Cup Water
- 6 Tablespoons White Vinegar
- 1 1/2 Tablespoons Red Wine Vinegar
- 1/2 Tablespoon Onion, freshly grated
- 1 Tablespoon Cornstarch
- 2 Teaspoons Dijon Mustard
- 2 Teaspoons Mustard Powder
- 1 Teaspoon Poppy Seeds
- 1/2 Teaspoon Sesame Oil
- 1/2 Teaspoon Onion Powder
- 1/2 Teaspoon Salt
- 1/4 Teaspoon Garlic Powder
- 1/4 Teaspoon Celery Seed
- 1/4 Teaspoon Paprika
- 1/4 Teaspoon Black Pepper
How to Make Homemade Sweet Onion Sauce
Step 1: Combine Ingredients
Add all ingredients to a saucepan.
Step 2: Cook the Mixture
Bring to a boil while whisking constantly. Let boil for 5 minutes. Then reduce heat to simmer for another 5 minutes, whisking continuously.
Step 3: Cool and Store
Remove from heat and allow to cool. Store in an airtight container in the refrigerator for up to 1 week.
This Homemade Sweet Onion Sauce serves about 8 people (or makes 2 cups) and is ready in just 15 minutes! Enjoy elevating your dishes with this flavorful condiment!
How to Serve Homemade Sweet Onion Sauce
Homemade Sweet Onion Sauce is versatile and can enhance a variety of dishes. Whether you’re using it as a dip or a dressing, it adds a delightful sweet and tangy flavor that complements many meals.
As a Sandwich Spread
- Elevate your sandwiches by spreading Homemade Sweet Onion Sauce on bread for added flavor.
With Fresh Salads
- Drizzle this sauce over fresh salads to give them a burst of sweetness and depth.
For Dipping Vegetables
- Serve the sauce as a dip for fresh vegetables. It pairs wonderfully with crunchy carrots, bell peppers, and cucumbers.
On Grilled Meats
- Brush this sauce on grilled chicken or pork for a tasty glaze that caramelizes beautifully.
In Wraps and Tacos
- Use it in wraps or tacos as a flavorful sauce that enhances the overall taste of your meal.
As a Marinade
- Marinate meats in Homemade Sweet Onion Sauce before grilling or baking to infuse them with rich flavors.

How to Perfect Homemade Sweet Onion Sauce
To achieve the best results with your Homemade Sweet Onion Sauce, consider these helpful tips.
- Use fresh ingredients: Freshly grated onion will provide a stronger flavor compared to pre-packaged options.
- Adjust sweetness: If you prefer a sweeter sauce, feel free to add more sugar gradually until you reach your desired taste.
- Whisk continuously: While cooking, whisking constantly helps prevent lumps and ensures an even consistency.
- Cool before storing: Allow the sauce to cool completely before transferring it to an airtight container to maintain freshness.
- Experiment with spices: Feel free to adjust spices like garlic powder or paprika based on your personal preference for an extra kick.
- Store properly: Keep the sauce in the refrigerator in an airtight container for up to one week for optimal flavor.
Best Side Dishes for Homemade Sweet Onion Sauce
Homemade Sweet Onion Sauce pairs beautifully with many side dishes, enhancing their flavors. Here are some great options:
- Grilled Corn on the Cob: Brush corn with the sauce after grilling for a unique twist.
- Sweet Potato Fries: Dip crispy sweet potato fries into the sauce for an unforgettable treat.
- Coleslaw: Mix Homemade Sweet Onion Sauce into coleslaw for an added layer of flavor.
- Baked Potatoes: Top baked potatoes with this sauce instead of traditional butter or sour cream.
- Roasted Vegetables: Drizzle over roasted veggies like Brussels sprouts or carrots for added taste.
- Rice Pilaf: Stir into rice pilaf as a dressing after cooking for enhanced flavor profiles.
Common Mistakes to Avoid
Making Homemade Sweet Onion Sauce can be simple, but there are common pitfalls that might affect the outcome. Here are some mistakes to watch out for:
- Skipping the whisking: Failing to whisk the mixture continuously while boiling can lead to lumps. Always keep stirring for a smooth sauce.
- Not measuring accurately: Using imprecise measurements can alter the flavor balance. Use measuring cups and spoons for best results.
- Ignoring cooling time: Rushing to use the sauce before it cools can result in a thinner consistency. Allow it to cool properly to thicken.
- Using stale ingredients: Old spices or vinegars can diminish flavor. Ensure your ingredients are fresh for the best taste.
- Storing improperly: Not using an airtight container can spoil your sauce quickly. Store it in a proper container in the refrigerator.

Storage & Reheating Instructions
Refrigerator Storage
- Store in an airtight container for up to one week.
- Label your container with the date to track freshness.
Freezing Homemade Sweet Onion Sauce
- Freeze in small portions using ice cube trays, then transfer to a freezer bag.
- It can last up to three months in the freezer.
Reheating Homemade Sweet Onion Sauce
- Oven: Preheat your oven to 350°F and warm in an oven-safe dish until heated through.
- Microwave: Place in a microwave-safe container and heat in 30-second intervals, stirring between each interval.
- Stovetop: Heat gently over low heat, stirring constantly until warmed.
Frequently Asked Questions
Here are some common questions regarding Homemade Sweet Onion Sauce.
How long does Homemade Sweet Onion Sauce last?
Homemade Sweet Onion Sauce lasts about one week when stored properly in the refrigerator.
Can I customize this sauce?
Absolutely! You can adjust sweetness by adding more sugar or tanginess with additional vinegar based on your personal taste.
Is Homemade Sweet Onion Sauce vegan?
Yes, this recipe is vegan-friendly as all ingredients used are plant-based.
What dishes pair well with Homemade Sweet Onion Sauce?
This sauce complements sandwiches, salads, and grilled vegetables beautifully, enhancing their flavors.
Final Thoughts
This Homemade Sweet Onion Sauce is not only easy to make but also incredibly versatile. Its sweet and tangy notes make it perfect for various dishes. Feel free to customize it according to your preferences; add more spices or adjust sweetness levels for a unique twist!

Homemade Sweet Onion Sauce
- Total Time: 15 minutes
- Yield: About 16 servings (2 cups) 1x
Description
Homemade Sweet Onion Sauce is a delectable blend of sweet and tangy flavors that instantly enhances any meal. This easy copycat recipe replicates the beloved Subway sauce, making it an ideal addition to sandwiches, salads, and dips. In just 15 minutes, you can create this versatile condiment using simple pantry ingredients. Perfect for gatherings or weeknight dinners, this sauce is sure to impress with its unique taste and adaptability.
Ingredients
- 1 Cup Sugar
- 1/2 Cup Water
- 6 Tablespoons White Vinegar
- 1 1/2 Tablespoons Red Wine Vinegar
- 1/2 Tablespoon Freshly Grated Onion
- 1 Tablespoon Cornstarch
- 2 Teaspoons Dijon Mustard
- 2 Teaspoons Mustard Powder
- 1 Teaspoon Poppy Seeds
- 1/2 Teaspoon Sesame Oil
Instructions
- Combine all ingredients in a saucepan.
- Bring the mixture to a boil while whisking constantly. Boil for 5 minutes, then reduce heat and simmer for another 5 minutes, continuing to whisk.
- Remove from heat and let cool. Store in an airtight container in the refrigerator for up to one week.
- Prep Time: 10 minutes
- Cook Time: 5 minutes
- Category: Condiment
- Method: Stovetop
- Cuisine: American
Nutrition
- Serving Size: 2 tablespoons (30g)
- Calories: 95
- Sugar: 23g
- Sodium: 150mg
- Fat: 0g
- Saturated Fat: 0g
- Unsaturated Fat: 0g
- Trans Fat: 0g
- Carbohydrates: 24g
- Fiber: 0g
- Protein: <1g
- Cholesterol: 0mg
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